Stoker



June-l5, 1937. o. N. MOORE El AL 2,084,060

STOKER v I Filed Sept. 21, 1954 2 Sheets-Sheet 1 fir? /V Mao/95m PayserP/Vaa as;

June ,1937. o. N. MOORE E! AL 2,084,060

35 by at substantially constant speed.

Patented June 15, 1937 UNITED STATES aosmeo s'roxEa om N. Moore and Robert P. Moore, Indianapolis, Ind.

Application September 21, 1934, Serial No. 744,916

2 Claims.

Our invention relates to coal stokers, and it is ourprimary object to produce a stoker in which the regulation of the coal feed is secured by an extremely simple and effective mechanism.

Other objects of our invention include the provision of means for preventing in the air-supply passages any accumulation of riddlings or small coal particles which find their way through the tuyeres of the fire-pot, and the provision of means for preventing any flow of gases rearwardly from the fire-pot through thejcoal-feed passage and coal-hopper.

The accompanying drawings illustrate our invention: Figs. 1 and 2 are perspective views of the completestoker assembly; Fig. 3 is a vertical section through the furnace, hopper, and stoker assembly, with the blower in elevation; Fig. 4 is a perspective view of the fire-pot and its associated base with a portion of theflre-pot wall broken away; and Fig. 5 is a fragmental vertical section on the line 55 of Fig. 3.

The stoker includes a coal-hopper Ill supported upon a suitable base II which also serves as a support for an electric motor I2 and a blower I3. Near its bottom, the'hopper Illhas a coal-discharge opening communicating with a circular coal-feed conduit l5 through which coal is fed to the fire pot, the movement of coal being accomplished by means of a helical feedscrew it which is disposed within the conduit l5 and which extends rearwardly across the bottom of the coal hopper. The feed screw I6 is connected by any suitable power-transmission mechanism with the motor l2 to be driven there- The fire-pot 20 to which coal is fed through the conduit I5 is conveniently of an inverted frusto-conica'l shape supported upon a hollowv base 2| of a generally semi-circular shape. The

walls of the fire-pot 2|I,are hollow and communicate with the interior of the base 2|. The inner surface of the fire pot is provided with tuyeres 22 through'which passes the air necessary to support combustion. At its lower end 5 the interior of the fire pot 2|! communicates through an elbow 23 with the forward end of the conduit l5.

The plane vertical face of the base 2| is'disposed toward thecoal hopper and is provided with a centrally located opening 24 for the reception of theforward end of the conduit I5. In addition, this vertical face of the base. is provided near one lower comer with a clean-out opening 25 and, near the opposite lower corner with an air-admission opening 28 to which air is supplied from the blower l3 through a conduit 21 that extends'through. the hopper-base II and that is provided with a damper 21'. The helical flight or rib of the feed-screw I6 is interrupted, preferably at or near the discharge opening of the coal hopper l0, and 'at this point of interruption we provideatransver'sely movable feed-regulating member. Conveniently, the feed-regulating member or valve 30 is vertically slidable in a suitable guide 3|, its position being controlled by a suitable operating member 32. At its lower end, the valve 30 is provided with anupwardly extending slot embracing the shaft of the feed screw, l6, as is clear from Fig. 5 so that, except for such slot, the valve 30can be operated to close the discharge opening of the hopper l0.

We have found it convenient to interrupt the helical rib of the feed screw l6 at several points within the hopper I0, as indicated by the numeral 34 in Fig. 3. Further, instead of sloping the side walls of the hopper III to a point closely adjacent the feed screw, we prefer to have such walls extend downward vertically to meet the plane horizontal base III of the hop- 25 per at points spaced a considerable distance from the feed screw It. We find that this arrangement prevents the tendency of the coal to arch over the feed screw.

At some point in its length, preferably near the fire pot 20; the coal-feed conduit I5. is provided in its upper surface with an opening communicating with a pipe 40 which extends verti cally beside the fire pot into the combustion chamber thereabove. The upper end of this pipe will be subject-to the partial vacuum created by the normal up-fiow of gases through the combustion chamber. This arrangement prevents gases from feeding backwards through the conduit l5 from the fire pot to the coal hopper, as any gases entering the conduit l5 from the fire-pot will be discharged upwardly through the pipe 40.

The clean-out opening 25 in the base 2| of the fire pot is. preferably provided with an outward'extension 25 -(see Fig. 4) which communicates with a pipe 42 extending vertically beside the fire pot 20 and discharging within the furnace above the fire pot. Air from the blower l3 discharging tangentially into the semi-circular base 2| of the fire pot will tend to flow around the curved wall thereof and to pick up from the floor of the base any fine particles of coal or ash which may happen to pass through the tuyeres 22. By the action of centrifugal force resulting a nace. valve 30 in thecoal-supply conduit l5 while the 5 The purpose of the gate valve 30 is to permit feed screw l6 and blower .l3continue to operate control of the quantity of coal fed relative to at constant relative speed. the amount of air supplied to the fire without the We claim as our invention:-,-- necessity for varying the relative speeds of the n a Sto a fi -Do having o lew walls in feed screw I 6 and the blower l3, which may pr vided with nw r y ope n y res; a hol- 10 therefore be driven at constant relative speed. w base supp a d -D e nt o o The valve member 30, controlling as it does the aid base communicating with the interior of effective size of the opening through which coal said walls, said base having a generally vertipasses from the hopper l0, regulates the amount cal curved wall, means for discharging m'r into is of coal which is fed at each revolution of the said base near the bottom thereof and tangenfeed screw. tially 'of said curved wall, said base being pro- Our stoker is installed in association with a vided with an opening positioned to receive air furnace as illustrated in Fig. 3. The fire-pot deflected by said wall, and a pipe communicat-' is located within the furnace and the coal-hoping with the interior of said base through such 20 per l0 and its associated parts are located near opening, said pipe extending upwardly to a point 20 but outside the furnace, the coal and air conabove and adjacent said fire-pot. 'duits l5 and 21 extending through the furnace 2. In a stoker, a fire-pot having hollow walls casing. The two pipes 40 and 42 extend upwardprovided with tuyres throughwhich air is disly beside the fire-pot and are located wholly charged into the fire, a chamber below said firewithin the furnace casing. pot and communicating with the space within In operation, the hopper I0 is filled with coal said hollow walls, means for blowing air into said which is fed to the fire pot by operation of the chamber and said hollow walls so that it is disfeed-screw IS. The feed-screw, being driven charged through said tuyres. from the blower-motor 12 operates whenever the OTTO N. MOORE. a0 blower operates, the motor usually being under ROBERT P. MOORE. 3o

Patent No. 2,084,060.

of the above numbered patent requiring correction as follows: second column, line 28, before the period at the end of claim 2 from the circular motion of air within the base 2 I, these fine particles will be carried toward the outside, and will pass through the opening 25' into the pipe 42, to be discharged within the furthe control of some automatic temperature responsive mechanism. 'The ratio between the rate of coal-supply and the rate of air supply may be varied to suit conditions by adjustment of the CERTIFICATE OF CORRECTION.

June 15, 1937.

one it, oons, ET AL.

It is hereby certified that error appears in the printed-specification Page 2, insert the words "and a separate conduit connecting said chamber to the fire zone of the fire-pot, the conduit-end which communicates with said chamber being in position to have fine particles of coal or ash which fall into said cham-- ber from the fire-pot blown into it by the air within the chamber and carried by the air through said conduit into said fire zonefand that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the, Patent Office.

. Signed. and sealed this 24th day of August, A. D. 1937.

Leslie Frazer (Seal) Acting Commissioner of Patents.

a nace. valve 30 in thecoal-supply conduit l5 while the 5 The purpose of the gate valve 30 is to permit feed screw l6 and blower .l3continue to operate control of the quantity of coal fed relative to at constant relative speed. the amount of air supplied to the fire without the We claim as our invention:-,-- necessity for varying the relative speeds of the n a Sto a fi -Do having o lew walls in feed screw I 6 and the blower l3, which may pr vided with nw r y ope n y res; a hol- 10 therefore be driven at constant relative speed. w base supp a d -D e nt o o The valve member 30, controlling as it does the aid base communicating with the interior of effective size of the opening through which coal said walls, said base having a generally vertipasses from the hopper l0, regulates the amount cal curved wall, means for discharging m'r into is of coal which is fed at each revolution of the said base near the bottom thereof and tangenfeed screw. tially 'of said curved wall, said base being pro- Our stoker is installed in association with a vided with an opening positioned to receive air furnace as illustrated in Fig. 3. The fire-pot deflected by said wall, and a pipe communicat-' is located within the furnace and the coal-hoping with the interior of said base through such 20 per l0 and its associated parts are located near opening, said pipe extending upwardly to a point 20 but outside the furnace, the coal and air conabove and adjacent said fire-pot. 'duits l5 and 21 extending through the furnace 2. In a stoker, a fire-pot having hollow walls casing. The two pipes 40 and 42 extend upwardprovided with tuyres throughwhich air is disly beside the fire-pot and are located wholly charged into the fire, a chamber below said firewithin the furnace casing. pot and communicating with the space within In operation, the hopper I0 is filled with coal said hollow walls, means for blowing air into said which is fed to the fire pot by operation of the chamber and said hollow walls so that it is disfeed-screw IS. The feed-screw, being driven charged through said tuyres. from the blower-motor 12 operates whenever the OTTO N. MOORE. a0 blower operates, the motor usually being under ROBERT P. MOORE. 3o

Patent No. 2,084,060.

of the above numbered patent requiring correction as follows: second column, line 28, before the period at the end of claim 2 from the circular motion of air within the base 2 I, these fine particles will be carried toward the outside, and will pass through the opening 25' into the pipe 42, to be discharged within the furthe control of some automatic temperature responsive mechanism. 'The ratio between the rate of coal-supply and the rate of air supply may be varied to suit conditions by adjustment of the CERTIFICATE OF CORRECTION.

June 15, 1937.

one it, oons, ET AL.

It is hereby certified that error appears in the printed-specification Page 2, insert the words "and a separate conduit connecting said chamber to the fire zone of the fire-pot, the conduit-end which communicates with said chamber being in position to have fine particles of coal or ash which fall into said cham-- ber from the fire-pot blown into it by the air within the chamber and carried by the air through said conduit into said fire zonefand that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the, Patent Office.

. Signed. and sealed this 24th day of August, A. D. 1937.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

